Hands-On Data Analysis with Pandas

Arithmetic and statistics

In the Describing and summarizing the data section of Chapter 2, Working with Pandas DataFrames, there was a table showing some operations that we could run on Series and DataFrame objects. Here, we are going to use some of those to create new columns and modify our data to see how we can use new data to draw some initial conclusions.

First, let's create a column with the Z-score for the volume traded in Facebook stock and use it to find the days where the Z-score is greater than 3 in absolute value. These values are more than three standard deviations from the mean, which may be abnormal (depending on the data). Remember from our discussion of Z-scores in Chapter 1, Introduction to Data Analysis, that we calculate ...